Compositions and methods for cleaning the gums

ABSTRACT

A composition for cleaning the gums comprising silica, water and a detergent, said composition having a RDA of less than 20.

BACKGROUND OF THE INVENTION

The present invention relates to a composition and method for cleaningthe gums. Denture wearers should remove their dentures periodically,preferably twice daily, and brush their gums with a cleansingcomposition using a brush having soft bristles. A gel composition forsuch use is disclosed in U.S. Pat. No. 4,428,929 (the "'929 patent"),the disclosure of which is hereby incorporated herein by reference. Thecomposition of the present invention provides formulations that aresuperior in appearance and "feel" to that of the gel of the '929 patent.

SUMMARY OF THE INVENTION

The present invention relates to a composition for cleaning the gumscomprising silica, water and a detergent, said composition having a RDA(Radioactive Dental Abrasion, also referred to as Relative DentalAbrasion) of less than 20, more preferably, an RDA of less than 15, andmost preferably an RDA of less than 10. In a preferred embodiment of thepresent invention, the composition also comprises sorbitol, polyethyleneglycol, glycerin, and cellulose gum. The formulation may also compriseone or more of flavor, sweetener, coloring material and one or morepreservatives. A preferred detergent for use in the composition of thepresent invention is sodium lauryl sulfate, a preferred silica isprecipitated hydrated silica, a preferred sweetener is sodium saccharin,and a preferred preservative is sodium benzoate.

The compositions of the present invention are preferably gels. Morepreferably, they are gels that are visually clear, i.e., substantiallytranslucent or transparent.

The present invention also relates to methods of cleaning the gumscomprising applying to the gums the foregoing compositions. Suchcompositions are preferably applied by brushing the gums using a brushthat has soft bristles.

DETAILED DESCRIPTION OF THE INVENTION

The silicas that may be used in the composition of the present inventionare those silicas that are capable of functioning as thickening agentswithout causing the composition to have an unacceptable amount ofabrasiveness for brushing the gums, i.e. their abrasiveness should besufficiently low so that the RDA of the formulation will be less than20. Silicas that are used as polishing agents in conventionaltoothpastes are likely to be too abrasive for use in the compositions ofthe present invention. An example of a type of silica that may be usedin formulations of the present invention is a non-precipitated silicasuch as a silica aerogel. The preferred silica is a precipitatedhydrated silica. Precipitated hydrated silicas are available fromDegussa Corporation as Sipernat 22S (trademark) and Sipernat 22LS(trademark).

The RDA of the formulations of the present invention may be measured bythe method disclosed by J. J. Hefferren in J. Dent. Res., 563-573,(1976).

A more preferred formulation of the present invention comprises thefollowing:

(a) non-crystallizing sorbitol solution-about 45 to about 55 parts byweight;

(b) water--about 15 to about 20 parts by weight;

(c) precipitated hydrated silica--about 12 to about 16 parts by weight;

(d) glycerin--about 9 to about 11 parts by weight;

(e) polyethylene glycol--about 2 to about 4 parts by weight;

(f) detergent (e.g., sodium lauryl sulfate)--about 2 to about 3 parts byweight

(g) flavor--0 to about 1.5 parts by weight;

(h) cellulose gum--about 0.4 to about 0.6 parts by weight; and

(i) sweetener (preferably, sweetener that does not promote tooth decayand/or has a strong sweetening power, such as sodium saccharin)--about0.2 to 0.3 parts by weight for sodium saccharin or an appropriate amount(i.e. having an equivalent sweetening effect) of another sweetener.

The foregoing formulation may also contain a preservative. Thepreservative should preferably be effective to prevent bacterial andfungal growth in the formulation for the desired shelf life and for areasonable period of use by the consumer. A preferred preservative issodium benzoate. When sodium benzoate is used as the preservative itwould be used in an amount of about 0.08 to about 0.12 parts by weight.The foregoing formulation may also contain coloring material. Suchcoloring material would generally be used in an amount of about 0.8 toabout 1.3 parts by weight of a 0.5 percent by weight aqueous solution.

A particularly preferred formulation of the present invention comprisesthe following:

    ______________________________________                                        Ingredients         Parts By Weight                                           ______________________________________                                        (a)    non-crystallizing sorbitol                                                                     50.00                                                        solution                                                               (b)    water            17.64                                                 (c)    precipitated hydrated silica                                                                   14.00                                                 (d)    glycerin         10.00                                                 (e)    polyethylene glycol                                                                            3.00                                                  (f)    sodium lauryl sulfate                                                                          2.40                                                  (g)    flavor           1.00                                                  (h)    cellulose gum    0.50                                                  (i)    sodium saccharin 0.25                                                  (j)    sodium benzoate  0.10                                                  (k)    coloring material                                                                              1.11                                                         (0.50% by weight aqueous                                                      solution)                                                              ______________________________________                                    

In the foregoing formulations, the preferred precipitated hydratedsilica is Sipernat 22S (trademark), Sipernat 22LS (trademark), or amixture of such silicas. More preferably, the precipitated hydratedsilica is a mixture of 11 parts by weight Sipernat 22S and 3 parts byweight Sipernat 22LS.

In the foregoing formulations, the preferred polyethylene glycol isPEG-6-32 (also known as Carbowax 1450 (trademark)), available from UnionCarbide Corporation.

In the foregoing formulations, the preferred coloring material is amixture of 0.68 parts by weight of D & C yellow #10 (0.50% by weightaqueous solution) and 0.43 parts by weight of FD & C Green #3 (0.50% byweight aqueous solution).

As used herein, the term non-crystallizing sorbitol solution refers toan aqueous solution that contains at least about 45 percent by weightsorbitol, at least about 20 percent by weight maltitol, and at leastabout 29 percent by weight water. This solution does not crystallize at0° C., while USP Sorbitol crystallizes at about 25° C. The preferredmaterial is LIPONIC 70-NC (trademark) available from Lipo Chemicals,Inc. of Paterson, N.J. The latter material contains 29-30 percent byweight water, 46-55 percent by weight sorbitol, 1-1.5 percent totalsugars (primarily maltose), the balance being predominantly maltitol (adimer of sorbitol) with a minor amount of higher molecular weight sugaralcohols.

A sorbitol solution containing about 60 to about 70 percent by weightsorbitol, preferably about 64 to about 70 percent by weight sorbitol andthe remainder water (said solution preferably consisting essentially ofsorbitol and water), may be substituted for the aforementionednon-crystallizing sorbitol solution in the formulations of the presentinvention. Other sweeteners that form viscous solutions, such as cornsyrup or glucose, may also be substituted for the non-crystallizingsorbitol solution in the formulations of the present invention.

The compositions of the present invention may conveniently be packagedin a lined aluminum tube or in a plastic laminated tube. Such tubes arecommonly used for oral care products such as toothpastes. When thecomposition of the present invention is used to clean the gums, anamount of gel that is about 1 to 2 centimeters in length is squeezed outof a conventional tube on to the surface of a brush having soft bristlesand the brush is then applied to the gums. One should be careful to usebristles that are sufficiently soft so that they will not irritate thegums. The bristles of the brush are desirably made from a soft plasticsuch as polyethylene. A blend of high and low density polyethylenes thatwill give a desired combination of stiffness and softness may be used.The brush used for cleaning the gums may have bristles protruding fromone surface of the brush head or two opposing surfaces of the brushhead. Alternatively, the bristles may protrude from all surfaces of thebrush head as shown in U.S. Pat. No. 4,328,604, the disclosure of whichis hereby incorporated herein by reference.

It will be understood that the method of the present invention is alsoapplicable to cleaning other oral tissues in addition to the gums butother than the teeth and that such cleaning is included within the scopeof the invention.

The following Example illustrates the formulations of the presentinvention:

EXAMPLE 1

Oral Gum Cleaner

The ingredients set forth below were combined as described below:

    ______________________________________                                        Ingredients          % by weight                                              ______________________________________                                        LIPONIC 70-NC (trademark)                                                                          50.00                                                    (sorbitol solution)                                                           Water                17.64                                                    Silica               14.00                                                    Glycerin             10.00                                                    PEG-6-32 (Polyethylene Glycol)                                                                     3.00                                                     Sodium Lauryl Sulfate                                                                              2.40                                                     Flavor               1.00                                                     Cellulose Gum        0.50                                                     Sodium Saccharin     0.25                                                     Sodium Benzoate      0.10                                                     D + C Yellow #10 (0.50% aqueous)                                                                   0.68                                                     FD + C Green #3 (0.50% aqueous)                                                                    0.43                                                                          100.00                                                   ______________________________________                                    

1. Melt the PEG-6-32 (polyethylene glycol) and add it to the previouslyheated LIPONIC 70-NC (trademark) sorbitol solution in a kettle (kettleA). Mix until homogeneous, maintaining the temperature at 70° C.

2. In a second kettle, disperse the cellulose gum in the glycerin. Mixuntil a uniform dispersion is obtained.

3. Add the cellulose gum and glycerin mixture prepared in step 2 tokettle A at 70° C. and slowly agitate for 5 minutes.

4. Combine the sodium saccharin and sodium benzoate in the water and mixat 70° C. Mix the yellow and green dyes into the resulting solution.

5. Add the solution prepared in step 4 to kettle A and mix with slowagitation at 70° C. until a uniform mixture is attained. Disperse thesilica into the resulting mixture and mix at 70° C. until a smoothconsistency is attained. Lower the temperature to 40° to 50° C. and thenadd the flavor, mixing until homogeneous. Dissolve the sodium laurylsulfate in water and add the solution to the gel, mixing untilhomogeneous. Then deaerate the gel.

EXAMPLE 2

The radioactive dentin abrasion (RDA) levels of the Oral Gum Cleaner ofExample 1, a conventional dentifrice (Advanced Formula Crest(trademark)), and water were determined as described below.

Procedure

The procedure used was the ADA recommended procedure (J. J. Hefferren,J. Dent. Res., 563-573 (1976)) for determination of dentifriceabrasivity. The dentin specimens (8) were irradiated in a neutron fluxin accordance with the ADA recommended procedure. The specimens werethen mounted in methylmethacrylate so they would fit in a V-8cross-brushing machine. The specimens were brushed for a 6000 stroke,precondition run using a slurry consisting of 10 g ADA referencematerial (calcium pyrophosphate) and 50 ml of a 0.5%carboxymethyl/cellulose/10% glycerin solution. The brushes used werethose specified by the ADA recommended procedure, and brush tension was150 g.

Following the precondition run, the test was performed using thespecified sandwich design as follows;

    ______________________________________                                        Run   Slurry                                                                  ______________________________________                                        1     ADA Reference Material  (10 g/50 ml)                                    2     Oral Gum Cleaner        (25 g/40 ml)                                    3     ADA Reference Material  (10 g/50 ml)                                    4     Advanced Formula Crest (trademark)                                                                    (25 g/40 ml)                                    5     ADA Reference Material  (10 g/50 ml)                                    6     Tap Water               (50 ml)                                         7     ADA Reference Material  (10 g/50 ml)                                    ______________________________________                                    

Three ml aliquotes were then removed from each slurry, dried and countedfor radiation using a geiger counter. The pre and post net CPM (countsper minute) of the ADA reference material for each test slurry was thencalculated and averaged to use in the calculation of RDA for each testmaterial. The ADA material was assigned a value of 100 and its ratio toeach test material was calculated.

Correction factors were prepared by adding 1 ml of a radioactivesolution and 1 ml of a neutralizing solution to slurries of the testmaterials and of the ADA reference material. Aliquots of these slurrieswere taken and dried along with the test slurry aliquots. They weresimilarly counted at the same time as the test aliquots. The net CPM ofthe ADA reference material correction factor aliquot was then divided bythe net CPM of each test material correction factor aliquot. Theresulting number was the correction factor for that specific slurry. Thecorrection factor was then applied to the mean RDA value for therespective group.

Results

The results are summarized in Table 1. As shown, the dentifrice slurryproduced significantly more abrasion to dentin than did water or theOral Gum Cleaner.

Conclusion

The Oral Gum Cleaner is not significantly more abrasive to dentin thanis water.

                  TABLE 1                                                         ______________________________________                                        RDA VALUES                                                                    Specimen Number                                                                           Oral Gum Cleaner                                                                            AF Crest   Water                                    ______________________________________                                        1           6.79          90.40       7.97                                    2           6.79          92.97      11.97                                    3           7.31          86.88       8.36                                    4           7.31          85.95      10.10                                    5           7.04          91.62      10.00                                    6           6.26          96.31      11.78                                    7           6.64          94.69       9.24                                    8           7.24          89.54      11.01                                    Raw Mean Score                                                                            6.92          91.04      10.05                                    ± S.E.M. 0.13           1.28       0.52                                    Self Absorption                                                                           1.11           1.21       0.60                                    Correction Factor                                                             Corrected Mean                                                                            7.68          110.16      6.03                                    Score                                                                         ± S.E.M. 0.14           1.55       0.31                                    ______________________________________                                    

What is claimed:
 1. A method of cleaning the gums of a denture wearer comprising applying to the gums after the dentures have been removed, periodically, a gum cleaner composition comprising silica in a cellulose gum gel, water and a detergent, said composition having an RDA of less than 20, said composition being not significantly more abrasive to dentin than water.
 2. A method according to claim 1, wherein said RDA is less than
 15. 3. A method according to claim 1, wherein said RDA is less than
 10. 4. A method according to claim 1, wherein said composition also comprises sorbitol, polyethylene glycol, glycerin and cellulose gum.
 5. A method according to claim 1, wherein said silica is precipitated hydrated silica.
 6. A method according to claim 2, wherein said silica is precipitated hydrated silica.
 7. A method according to claim 3, wherein said silica is precipitated hydrated silica. 